The purpose of this project is to study the response of preschool children to dental stress. Children, 2 to 5 years old, with no previous dental experience will be studied longitudinally for three years during periodic dental visits. Three factors will be examined: 1) The effect of age on the child's response to the initial dental experience and to continued periodic dental care. 2) The effect of non-stressful exam visits on the young child's response to eventual stressful treatment procedures, and 3) The effect of stressful treatment experiences on children's response to subsequent dental care. The child's response will be assessed, using a combination of human figure drawing, clinical ratings of cooperative behavior. A multivariate analysis of variance for repeated measures will be used to test for significant effects. Physiological, self-report and clinical measures. The physiological measures include heart rate, skin conductance, E.M.G. and skin temperature. The self-report measures are the picture test and the human figure drawing. The clinical measures include ratings of anxiety and cooperative behavior.